The X-Series earmuffs are 3M's latest advancement in hearing conservation. New technologies in comfort, design and protection all come together in this groundbreaking earmuff line. The X4A utilises a newly designed spacer, specially formulated foam liners and innovative ear cushions to help improve attenuation. This lightweight, lower-profile earmuff helps with compatibility with other personal protective equipment and is designed for protection against moderate-to-high level industrial noise and other loud sounds. Colour: Hi Vis/Black. It Features: an electrically insulated wire headband, often referred to as dielectric". The wire headband offers consistent pressure over prolonged wearing periods. Earcup pivot points tilt for optimum comfort and efficiency. Noise Reduction Rating: SNR 33dB. CSA Class AL. NOTE: The X-Series (over-the-head) headband version is electrically insulated - sometimes referred to as "dielectric". The metal components of the headband have been covered by non-conductive material for use in a low voltage electrical hazard (less than 440 V ac). High Frequency = 36dB, Medium Frequency = 30dB, Low Frequency = 22dB"